good afternoon

From Longman Dictionary of Contemporary Englishgood afternoongood ˌafterˈnoon ●●●S3 formalHELLOused to say hello when you are greeting someone in the afternoon, especially someone you do not know → good evening, good morningRegisterIn informal everyday English, people often just say Afternoon. If you don't want to sound formal or informal, you can just say Hello:Afternoon, everyone.